Multiple sclerosis and myasthenia gravis may be autoimmune diseases with loss of immunological tolerance to host tissue. We propose to investigate patterns of autologous recongition in patients with multiple sclerosis (MS) and myasthenia gravis (MG). We plan to do this in two ways. The first is to use the autologous mixed lympocyte culture system. The second is to analyse patterns of self recongition in a cellular cytotoxic assay in which hapten-modified syngeneic cells are the stimulators of autologous T-cells. All studies in these patient populations will be correlated with their HLA phenotypes to determine if major histocompatibility complex associated genes are correlated with the above noted autologous reactions.